I am now in the process of installing Hamsticks for 20 and 40 meters on the
trunk lid of my mid-sized sedan. I have not configured the HF rig and cables
yet.

I did some tests with the Autek RF-1. I found I was able to resonant
the antennas close to where the spec sheets show them to be set at. This is
referenced to the length of the whip section.

The one thing I'm finding is that the impedance is rather low at resonance.
30 ohms in one case. I don't remember which band that was. For 20 meters
the SWR was 1.7 to 1. On 40 meters, the SWR was 2.5 to 1. Resonance was
tuned for recognized QRP CW frequencies.